14 Jan
2016
14 Jan
'16
10:26 p.m.
Johnny,?
When the area routers in the other area are on the same LAN then the bridge w?ill only be
involved if there is another area router in that other area on the remote side of the
bridge program.
And will (very likely) slow down communications.
Can the bridge program detect whether there are area routers for the dame area at both
ends and favor the local one, possibly block advertising of the remote area router?
Hans
Verzonden?vanaf?mijn?BlackBerry?10-smartphone.
? Origineel bericht ?
Van: Johnny Billquist
Verzonden: donderdag 14 januari 2016 22:06
Aan: hecnet at Update.UU.SE
Beantwoorden: hecnet at Update.UU.SE
Onderwerp: Re: [HECnet] Multinet peerings...?
On 2016-01-14 21:38, Peter Lothberg wrote:
If all links in HECNet where point-to-point, with the same metric on
both sides, it will most likely be almost *perfect* by itself.
The complex movie is when they *THINK* they are all on the same
ethernet with metric 1.....
Well, in all honesty, default cost for ethernet links in VMS is 4, and
in RSX is 3...
So, if you want to favor a different link, set the cost to less.
But you are blindly assuming that Multinet (or other) point-to-point
links are better. That one I still do not see. There are definitely
cases where it can be worse.
The worst thing about the bridge is, as I wrote in another mail, is when
you are on an ethernet segment, and you want to talk to a different
area, which have several area routers on that same ethernet segment you
are on, in which case you might end up going through pretty bad hopping.
Johnny
On Jan 14, 2016, at 3:02 PM, Peter Lothberg
<roll at Stupi.SE> wrote:
If costs are the same at both ends of a link, that will certainly
help. Then again, it is quite possible for two paths to have equal
cost, and if so, DECnet implementations will pick one of the two, in
a way that is not specified.
paul The values are somewhat arbitrary; it doesn't
really matter what
scheme you use but if you are inconsistent the routing may be
surprising.
The routing spec has a suggested algorithm (100,000/line speed)
which may have made sense in the old days but for modern networks
isn't terribly useful.
paul
What I wanted to get to was a scenario where traffic was symetric
between two nodes, eg, use the same links from a-b as b-a, it makes it
much easier to understand what's wrong when things behave funny...